Stave coolers for a metallurgical furnace are well known in the art. They are used to cover the inner wall of the outer shell of the metallurgical furnace, such as e.g. a blast furnace or electric arc furnace, to provide: (1) a heat evacuating protection screen between the interior of the furnace and the outer furnace shell; and (2) an anchoring means for a refractory or metallic brick lining, a refractory guniting or a process generated accretion layer inside the furnace. Originally, the stave coolers have been cast iron plates with cooling pipes cast therein. As an alternative to cast iron staves, copper staves have been developed. Nowadays, most stave coolers for high heat loads for a metallurgical furnace are made of copper, a copper alloy or, more recently, of steel.
A copper stave cooler for a blast furnace is e.g. disclosed in German patent DE 2907511 C2. It comprises a panel-like body having a hot face (i.e. the face facing the interior of the furnace) that is subdivided by parallel grooves into lamellar ribs. The object of these grooves and ribs, which preferably have a dovetail (or swallowtail) cross-section and are arranged horizontally when the stave cooler is mounted on the furnace shell, is to anchor a refractory or metallic brick lining, a refractory guniting material or a process generated accretion layer to the hot face of the stave cooler. Drilled cooling channels extend through the panel-like body in proximity of the rear face, i.e. the cold face of the stave cooler, perpendicularly to the horizontal grooves and ribs.
The refractory or metallic brick lining, the refractory guniting material or the process generated accretion layer forms a protective lining arranged in front the hot face of the panel-like body. This protective lining is useful in protecting the stave cooler from deterioration caused by the harsh environment reigning inside the furnace. In practice, the protective lining is subject to erosion such that the panel-like body may be exposed to the harsh environment of the furnace, resulting, in turn, in damage to the stave cooler.
Abrasion of the protective lining and the stave cooler may further be caused by the accumulation of unreduced material against the protective lining or the stave cooler, especially at the bosh and belly level of the metallurgical furnace, which are the cylindrical, respectively conical convergent parts of the furnace.
In U.S. Pat. No. 3,881,860, the stave cooler is provided with a projection on its front face in order to support the protective lining. A cooling channel is arranged through the projection. U.S. Pat. No. 3,881,860 recognizes the problem that the protective lining can erode and thus expose the stave cooler, and especially its projection, to the harsh conditions in the metallurgical furnace. An attempt is made to avoid the problems of cooling fluid leaking into the furnace by providing improved cooling to the projection and thus prevent the projection from being damaged. This solution can however not adequately protect the protrusion, or the stave cooler itself, from being damaged by the harsh conditions reigning in the metallurgical furnace.